On-Farm Evaluation of Maize and Legume Intercropping for Improved Crop Productivity in the Mid Hills of Nepal
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On-farm evaluation of maize and legume intercropping for improved crop productivity in the mid hills of Nepal Name student(s): Arun Thapa Period: 6th Period Farming Systems Ecology Group Droevendaalsesteeg 1 – 6708 PB Wageningen - The Netherlands ___________________________________________________________________________ i On-farm evaluation of maize and legume intercropping for improved crop productivity in the mid hills of Nepal Name student(s): Arun Thapa Registration number student: 810312827090 Credits: 36 ECTs Code number/name course: FSE- 80436 Period: 6th Period Supervisor(s): Maria Victoria Alomia Hinojosa, Jeroen Groot Examiner: dr.ing. Johannes Scholberg i PREFACE This thesis is submitted in partial fulfilment of the requirement for a Master degree in Plant Science. It contains work done from June 2014 to February 2015. The writing of the report has gone through ups and downs. Especially in the beginning I experienced trouble defining the research topic. This was finally succeeded with the support of my supervisors of Farming System Ecology group. This thesis is primarily aimed at farmers in mid hills of Nepal where large proportion of population rely on maize based farming system. I hope it will be of interest to the scientific and academic communities as it tries to look for compatibility of research on intercropping on farmers’ fields. This report summarises 8 months joyful hardship job with a hope to synthesise good results with recommendations. First of all, I would like to thank The Netherlands organization for international cooperation in higher education (Nuffic) for the Netherland Fellowship Programmes that they offered me to pursue my M.Sc. studies. I also extend my gratitude to Wageningen University for granting me a permission to participate in the course of Plant Science with specialization on Crop Science. I am deeply indebted to my supervisor dr.ir. Jeroen Groot of the Farming System Ecology group, whose interest in my work has been a constant source of inspiration. My gratitude are extended to Maria Victoria Alomia Hinojosa, Ph.D. candidate of Farming System Ecology group, for her comments and suggestions from the planning stage of experiment to accomplishment of the field experiment. In the finishing stages, Dr Groot and ir. Victoria’s attentions are gratefully acknowledged. I also thank Mr Resham K.C. and Mr. Krishna Gupta, Field supervisors of CIMMYT- CISA (Nepal) and Mr. Sudip Shahi, intern on CIMMYT-CISA (Nepal) who helped me during my field work with untiring interest. The Regional Agriculture Research Centre (RARS), Khajura, Nepal is indeed acknowledged for allowing me to make use of their laboratory. Finally I sincerely want to thank my family and friends for their moral support and patience. Arun Thapa ii ABSTRACT An on-farm experiment on maize and legume intercropping was conducted on local farmers’ fields in Dadeldhura district, far western region of Nepal under rain fed conditions during the rainy season from June to November, 2014. The objective of this study was to evaluate the effect of maize-legume intercropping systems for improved crop productivity in maize-based farming systems in the mid hills of Nepal. Treatments followed in this experiment were maize sole (Mz), soybean sole (Sb), cowpea sole (Cp), maize-soybean (MzSb) with 1:1 row arrangement and maize-cowpea (MzCp) with 1:1 row arrangement. Maize grain yield and morphological plant parameters (plant height, leaf length, leaf width, active leaf number, girth, grain number per cob) of maize were not affected by any of the cropping systems showing strong competitive ability of maize in intercropping. Soybean plant parameters (plant height, number of nodes, number of branch, branch weight, number of leaves, leaves weight, number of pods per plant) were adversely affected by the presence of maize plants, whereas for cowpea there was no difference in plant parameters (pod length and number of pods per plant) between sole cowpea and the intercropping system. Grain yield of soybean and fresh pod yield of cowpea were significantly reduced by 58% and 46% respectively in intercropping compared to sole cultivation. Higher light interception was observed in intercrops, maize-soybean (MzSb) and maize-cowpea (MzCp), at 60 and 67 days after sowing (DAS) compared to sole cropping. At 50 DAS lower weed density was observed in intercropping systems than in sole maize and sole soybean. Land Equivalent Ratio was greater than one in intercropping systems, 1.54 and 1.69 for maize-soybean (MzSb) and maize- cowpea (MzCp), respectively. The same trend was observed for Area Time Equivalent Ratio for maize-soybean (MzSb) and maize-cowpea (MzCp) with value of 1.39 and 1.61, respectively. The economic evaluation on the other hand indicated that net benefit was higher for maize-cowpea (MzCp) intercropping but from marginal analysis higher return benefit (832 %) was obtained in maize-soybean (MzSb). Key words : maize, legumes, intercropping, cropping systems, sole cropping iii LIST OF ABBREVIATION AGDP Agriculture Gross Domestic Product ATER Area Time Equivalent Ratio CBS Central Bureau of Statistics CIMMYT International Maize and Wheat Improvement Centre DAP Di-Ammonium Phosphate DAS Days After Sowing DM Dry Matter EC Emulsifiable Concentrate FP Farmer Practice FWE Fresh Weight Ear FWG Fresh Weight Grain FYM Farm Yard Manure GFB Gross Field Benefit Ha Hectare HH House Hold HI Harvest Index LAI Leaf Area Index LER Land Equivalent Ratio LSD Least Significant Difference LU Livestock Unit MC Moisture Content MOP Muriate of Potash MRR Marginal Rate of Return NB Net Benefit NRs Nepalese Rupees NLSS Nepal Living Standard Survey OM Organic Matter PAR Photosynthetically Active Radiation TVC Total Variable Cost VDC Village Development Committee iv LIST OF TABLES Table 1. Soil properties of different farms on two experimental sites. .................................... 13 Table 2. Participating farmers at on-farm trial on two experimental sites. .............................. 14 Table 3. Effect of cropping system on leaf length and leaf width of maize on different Days after sowing (DAS). ................................................................................................... 25 Table 4. Effect of cropping system on maize yield characteristics .......................................... 25 Table 5. Effect of cropping system on soybean vegetative growth and yield parameters. ...... 26 Table 6. Effect of cropping system on cowpea yield parameters. ............................................ 26 Table 7. Effect cropping system on yield ................................................................................. 30 Table 8. Effect of cropping system on partial Land Equivalent Ratio, Total Land Equivalent Ratio (LER) and Area Time Equivalent Ratio (ATER) ............................................. 32 Table 9. Effect of cropping system on maize-legume stover Dry Matter (DM) yield. ............ 32 Table 10. Effect of cropping system on Harvest Index of maize, soybean and cowpea .......... 34 Table 11. Net benefit analysis of different cropping system. ................................................... 34 Table 12. Marginal rate of return analysis of different cropping system ................................. 35 Table 13. Socioeconomic categorization of participating farmers in study. ............................ 36 Table 14. Farmers’ perspectives on practices applied in the field trial. ................................... 41 Table 15. Shift in production factors ........................................................................................ 50 v LIST OF FIGURES Figure 1. Map indicating Experimental sites in Far western region of Nepal. ......................... 12 Figure 2. Monthly rainfall and mean air temperature during growing season 2014. ............... 13 Figure 3. Row arrangement of maize ‘Mz’ ( ), soybean ‘Sb’ ( ) and cowpea ‘Cp’ ( ) for different cropping system. .................................................................................. 15 Figure 4. Effect of cropping system on maize plant height on different days after sowing (DAS). ...................................................................................................................... 24 Figure 5. Effect of cropping system on weed density per 0.25 m2 ........................................... 27 Figure 6. Effect of cropping system on weed fresh weight. ..................................................... 28 Figure 7. Photosynthetically Active Radiation (PAR) interception of different cropping system on different days after sowing (DAS). ......................................................... 29 Figure 8. Effect of cropping system on Leaf Area Index (LAI). .............................................. 29 Figure 9. Influence of Leaf Area Index (LAI) on light interception. ....................................... 30 Figure 10. Effect of cropping system on crop yields at different farm on two different sites . 31 Figure 11. Effect of cropping system on maize and legume stover DM yield at different farm on two different sites. ............................................................................................... 33 Figure 12. Net benefit curve of different cropping system. ..................................................... 36 Figure 13. Adoption of different cropping system by farmers in Kharif (rainy) season (Survey report, Victoria, 2014). ............................................................................................ 37 Figure 14.